#include <bits/stdc++.h>
//#include <chrono>
//#pragma GCC optimize("Ofast")
using namespace std;
#define reps(i,s,n) for(int i = s; i < n; i++)
#define rep(i,n) reps(i,0,n)
#define Rreps(i,n,e) for(int i = n - 1; i >= e; --i)
#define Rrep(i,n) Rreps(i,n,0)
#define ALL(a) a.begin(), a.end()
#define fi first
#define se second

using ll = long long;
using vec = vector<ll>;
using mat = vector<vec>;

ll N,M,H,W,Q,K,A,B;
string S;
typedef pair<ll, ll> P;
const ll INF = (1LL<<58);

int main() {
    cin>>A>>B;
    ((A %= 12) *= 30 * 120) += B * 60;
    B *= 6 * 120;
    if(A < B) A += 360 * 120;
    ll res(0);
    while(A + 1 >= B + 12){
        ++A;
        B += 12;
        ++res;
    }
    cout<<res<<endl;
}